diff --git a/middleware/flow/src/dto/flow_external_dto.rs b/middleware/flow/src/dto/flow_external_dto.rs
index 766ff4f1b..499abcf61 100644
--- a/middleware/flow/src/dto/flow_external_dto.rs
+++ b/middleware/flow/src/dto/flow_external_dto.rs
@@ -34,6 +34,7 @@ pub enum FlowExternalKind {
 #[derive(Debug, Deserialize, Serialize, poem_openapi::Object, Clone)]
 pub struct FlowExternalParams {
     pub rel_tag: Option<String>,
+    pub rel_kind: Option<String>,
     pub var_id: Option<String>,
     pub var_name: Option<String>,
     pub value: Option<Value>,
diff --git a/middleware/flow/src/dto/flow_transition_dto.rs b/middleware/flow/src/dto/flow_transition_dto.rs
index 168fec12c..c71209f46 100644
--- a/middleware/flow/src/dto/flow_transition_dto.rs
+++ b/middleware/flow/src/dto/flow_transition_dto.rs
@@ -316,15 +316,15 @@ pub enum StateChangeConditionOp {
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Debug, poem_openapi::Enum)]
 pub enum TagRelKind {
-    ParentFeed,
-    SubFeed,
+    Default,
+    ParentOrSub,
 }
 
 impl From<TagRelKind> for String {
     fn from(kind: TagRelKind) -> Self {
         match kind {
-            TagRelKind::ParentFeed => "PARENT_FEED".to_string(),
-            TagRelKind::SubFeed => "SUB_FEED".to_string(),
+            TagRelKind::Default => "DEFAULT".to_string(),
+            TagRelKind::ParentOrSub => "PARENT_OR_SUB".to_string(),
         }
     }
 }
diff --git a/middleware/flow/src/serv/flow_external_serv.rs b/middleware/flow/src/serv/flow_external_serv.rs
index 98d750e4e..d0569b256 100644
--- a/middleware/flow/src/serv/flow_external_serv.rs
+++ b/middleware/flow/src/serv/flow_external_serv.rs
@@ -13,7 +13,7 @@ use crate::{
             FlowExternalFetchRelObjResp, FlowExternalKind, FlowExternalModifyFieldResp, FlowExternalNotifyChangesResp, FlowExternalParams, FlowExternalQueryFieldResp,
             FlowExternalReq, FlowExternalResp,
         },
-        flow_state_dto::FlowSysStateKind,
+        flow_state_dto::FlowSysStateKind, flow_transition_dto::TagRelKind,
     },
     flow_config::FlowConfig,
     flow_constants,
@@ -26,7 +26,7 @@ impl FlowExternalServ {
         tag: &str,
         inst_id: &str,
         rel_business_obj_id: &str,
-        rel_tags: Vec<String>,
+        rel_tags: Vec<(String, Option<TagRelKind>)>,
         ctx: &TardisContext,
         funs: &TardisFunsInst,
     ) -> TardisResult<FlowExternalFetchRelObjResp> {
@@ -39,8 +39,9 @@ impl FlowExternalServ {
             curr_bus_obj_id: rel_business_obj_id.to_string(),
             params: rel_tags
                 .into_iter()
-                .map(|tag| FlowExternalParams {
+                .map(|(tag, kind)| FlowExternalParams {
                     rel_tag: Some(tag),
+                    rel_kind: kind.map(String::from),
                     var_id: None,
                     var_name: None,
                     value: None,
diff --git a/middleware/flow/src/serv/flow_inst_serv.rs b/middleware/flow/src/serv/flow_inst_serv.rs
index b1e23e806..02b20d387 100644
--- a/middleware/flow/src/serv/flow_inst_serv.rs
+++ b/middleware/flow/src/serv/flow_inst_serv.rs
@@ -707,6 +707,7 @@ impl FlowInstServ {
             let mut params = vec![];
             for (var_name, value) in vars {
                 params.push(FlowExternalParams {
+                    rel_kind: None,
                     rel_tag: None,
                     var_name: Some(var_name.clone()),
                     var_id: None,
@@ -852,13 +853,8 @@ impl FlowInstServ {
                         }
                         let rel_tag = change_info.obj_tag.unwrap_or_default();
                         if !rel_tag.is_empty() {
-                            let obj_tag = if let Some(obj_tag_rel_kind) = change_info.obj_tag_rel_kind.clone() {
-                                String::from(obj_tag_rel_kind)
-                            } else {
-                                rel_tag.clone()
-                            };
                             let mut resp =
-                                FlowExternalServ::do_fetch_rel_obj(&current_model.tag, &current_inst.id, &current_inst.rel_business_obj_id, vec![obj_tag], ctx, funs).await?;
+                                FlowExternalServ::do_fetch_rel_obj(&current_model.tag, &current_inst.id, &current_inst.rel_business_obj_id, vec![(rel_tag.clone(), change_info.obj_tag_rel_kind.clone())], ctx, funs).await?;
                             if !resp.rel_bus_objs.is_empty() {
                                 for rel_bus_obj_id in resp.rel_bus_objs.pop().unwrap().rel_bus_obj_ids {
                                     let inst_id = Self::get_inst_ids_by_rel_business_obj_id(vec![rel_bus_obj_id.clone()], funs, ctx).await?.pop().unwrap_or_default();
@@ -871,6 +867,7 @@ impl FlowInstServ {
                                         None,
                                         None,
                                         vec![FlowExternalParams {
+                                            rel_kind: None,
                                             rel_tag: None,
                                             var_id: None,
                                             var_name: Some(change_info.var_name.clone()),
@@ -893,6 +890,7 @@ impl FlowInstServ {
                                 None,
                                 None,
                                 vec![FlowExternalParams {
+                                    rel_kind: None,
                                     rel_tag: None,
                                     var_id: None,
                                     var_name: Some(change_info.var_name.clone()),
@@ -908,13 +906,8 @@ impl FlowInstServ {
                 }
                 FlowTransitionActionChangeKind::State => {
                     if let Some(change_info) = post_change.state_change_info {
-                        let obj_tag = if let Some(obj_tag_rel_kind) = change_info.obj_tag_rel_kind.clone() {
-                            String::from(obj_tag_rel_kind)
-                        } else {
-                            change_info.obj_tag.clone()
-                        };
                         let mut resp =
-                            FlowExternalServ::do_fetch_rel_obj(&current_model.tag, &current_inst.id, &current_inst.rel_business_obj_id, vec![obj_tag], ctx, funs).await?;
+                            FlowExternalServ::do_fetch_rel_obj(&current_model.tag, &current_inst.id, &current_inst.rel_business_obj_id, vec![(change_info.obj_tag.clone(), change_info.obj_tag_rel_kind.clone())], ctx, funs).await?;
                         if !resp.rel_bus_objs.is_empty() {
                             let inst_ids = Self::find_inst_ids_by_rel_obj_ids(resp.rel_bus_objs.pop().unwrap().rel_bus_obj_ids, &change_info, funs, ctx).await?;
                             Self::do_modify_state_by_post_action(inst_ids, &change_info, updated_instance_list, funs, ctx).await?;
@@ -943,12 +936,7 @@ impl FlowInstServ {
                     let mut rel_tags = vec![];
                     for condition_item in change_condition.conditions.iter() {
                         if condition_item.obj_tag.is_some() && !condition_item.state_id.is_empty() {
-                            let obj_tag = if let Some(obj_tag_rel_kind) = condition_item.obj_tag_rel_kind.clone() {
-                                String::from(obj_tag_rel_kind)
-                            } else {
-                                condition_item.obj_tag.clone().unwrap()
-                            };
-                            rel_tags.push(obj_tag);
+                            rel_tags.push((condition_item.obj_tag.clone().unwrap(), condition_item.obj_tag_rel_kind.clone()));
                         }
                     }
                     let inst_id = Self::get_inst_ids_by_rel_business_obj_id(vec![rel_obj_id.clone()], funs, ctx).await?.pop().unwrap_or_default();